1. Field of the Invention
The present invention relates to a flexible exhaust emission aftertreatment system for compression cycle diesel engines.
The present invention further relates to a flexible exhaust emission aftertreatment system having synchronously operated valves to direct the flow of exhaust gas through the system responsive to the engine control module or driver input.
The present invention further relates to a flexible exhaust emission aftertreatment system having synchronously operated valves to direct the flow of exhaust gas through the system responsive to the engine control module or driver input wherein one treatment removes Particulate Matter from the exhaust gas flow and another treatment removes nitric oxides (NOx) emission from the exhaust gas flow.
The present invention further relates to a flexible exhaust emission aftertreatment system having synchronously operated valves to direct the flow of exhaust gas through the system responsive to the engine control module wherein the system is comprised of a Diesel Particulate Filer to remove Particulate Matter from the exhaust gas flow and a Selective Catalyst Reduction (SCR) system to remove NOx from the exhaust gas flow.
The present invention further relates to a flexible exhaust emission aftertreatment system to allow flexibility for exhaust gas to flow through particulate matter aftertreatment first and through NOx aftertreatment second, or through NOx aftertreatment first and through particulate matter aftertreatment second, or only through NOx aftertreatment bypassing particulate matter aftertreatment or only through particulate matter aftertreatment bypassing NOx aftertreatment.
2. Description of the Related Art
Cornelison, U.S. Pat. No. 4,725,411 discloses an exhaust treatment system in parallel to having a butterfly valve arrangement in the y-shaped exhaust connections between the treatment devices. The butterfly valve responds to pressure drops in the engine as well as to pressure changes in the exhaust system to direct the flow of the exhaust gases from one exhaust treatment device to another. Specifically, when a pressure change occurs the valve shuts the exhaust gas flow off to that particular treatment device and direct the exhaust gas flow to the other treatment device thereby allowing the affected treatment device to burn off any exhaust particulates which may have fouled the system.
Gillingham et al., U.S. Pat. No. 5,246,205 discloses a poppet valve assembly for use in an exhaust system. The poppet valve is used in an assembly to provide control of hot gas flows included through exhaust systems.
Scappatura U.S. Pat. No. 6,240,725 discloses an apparatus and method for the removal of carbon particles (soot), odor, gas and particulate from the exhaust of a diesel engine. The method includes a carbon (soot) collector which collects the carbon and noxious odor which is connected to the catalytic converter of the engine, then enters a heat exchanger for cooling and condensing a major portion of the exhaust gas into a liquid condensate. The condensate enters a reactor that neutralizes any acids present. The non-condensate gases flow to a second reactor where a second chemical reaction absorbs carbon monoxide and nitrogen oxide.
Kakwani et al., U.S. Pat. No. 6,826,906 discloses a diesel engine exhaust system that uses catalyzed soot filters for particulate matter reduction and urea Selective Catalyst reduction (SCR) catalysts and urea for NOx reduction on diesel engines in a combined system to lower particulate and NOx at the same time.
Kakwani et al., U.S. Patent Application Publication No. US2005/0056004 A1 discloses a diesel engine aftertreatment exhaust system that uses catalyzed soot filers for particulate matter reduction and urea SCR catalyst for NOx reduction on diesel engines in a combined system to lower particulate matter and NOx at the same time.